Thomas called Didymus, one of the twelve was not with them when Jesus appeared to the disciples. The others disciples told him about the appearance of Jesus who had earlier before the crucifixion assured them of his resurrection, but Thomas refused to believe. He said "except i shall see in his hand the print of the nails and put my finger into his side, i will not believe".
This can be described as the highest level of unbelief, considering the fact that Thomas was with Jesus, he saw the great miracles performed,yet he doubted the Master's statement. Jesus can never lie.
Spiritually speaking, many today are like Brother Thomas. They have seen the hand work of God, and had experienced great miracles,signs and wonders. They had seen, heard about Gods work in the lives of others, yet they are possessed by the spirit of unbelief.
The Spirit of unbelief makes one who had enjoyed miracles before to begin to doubt the same God who bestowed him multiples miracles earlier. The spirit of unbelief wants a man to see before he beliefs. It says "seeing is believing". The spirit of unbelief is the spirit of Thomas that wants its victims to see beyond a reasonable doubt before exercising faith, which is contrary to the law of faith.
Dear #steemitchurch, Thomas doubted because of unbelief which is very common in Christians nowadays. The bible says the Just shall live by faith, have faith and you will overcome.